The Kenmu Restoration and Sword Culture: How Emperor Go-Daigo's Anti-Shogunate Movement Transformed Blade Production in the Age of Courts

What Was the Kenmu Restoration?——The Fall of the Kamakura Shogunate and the Void in Samurai Rule

In 1333, Emperor Godaigo (後醍醐天皇) with the cooperation of Ashikaga Takauji and Nitta Yoshisada overthrew the Kamakura Shogunate and began direct imperial rule known as the "Kenmu Restoration." Ending samurai government and implementing unprecedented direct rule by the imperial court would collapse in just over three years, but this brief period became an extremely important turning point in the history of Japanese swords.

The period from 1333 to 1336 when the Kenmu Restoration began was a transitional era in which the sword forms of the late Kamakura period were dismantled and new sword forms of the Northern and Southern Courts period began to emerge. Swordsmiths of this era faced the loss of stable large-scale orders from the shogunate while simultaneously confronting rapidly increased weapons demands due to internal conflict.

Sword Form Changes Around the Kenmu Period——Transition from Late Kamakura to Northern and Southern Courts

Late Kamakura period swords (late 13th to early 14th century) possessed relatively well-proportioned forms. The sori was primarily of the waist-curve type, and the kissaki often featured a shape called inokubi-kissaki—small and rounded in appearance. This also resulted from actual combat demands following the Mongol Invasions (1274, 1281) that required sturdy swords.

From the Kenmu Restoration period (1333–1336) onward, this tendency rapidly changed. The success of Emperor Godaigo's campaign to overthrow the shogunate and the Northern and Southern Courts conflict that immediately followed (1336–) brought increased scale and prolongation of warfare, imposing new functional demands on swords.

The most conspicuous change was the enlargement of the blade. From the Kenmu period through the early Northern and Southern Courts period, blade length increased substantially, and large swords called daitachi and nodachi with blade lengths exceeding 90 centimeters began to be mass-produced. This reflected the transition from mounted combat to group combat on foot, demonstrating that longer-reaching weapons gained superiority on the battlefield.

Swordsmiths and Changes in Supply Systems During the Kenmu Period

The Kamakura Shogunate, as a samurai government headed by the Hōjō Tokusō family, maintained a stable system of sword supply to its vassal samurai. Official swordsmiths such as Masamune of Sōshū existed, and high-level techniques were inherited under the shogunate's patronage.

The Kenmu Restoration completely transformed this system. Swordsmiths of Sōshū who lost the shogunate's patronage sought new patrons—some joining Ashikaga Takauji's forces, others siding with Emperor Godaigo. Swordsmiths such as Kaneshige, Hiromitsu, and Akihiro who were active from the Kenmu period through the early Northern and Southern Courts period refined their techniques with new daimyo and military commanders as primary clients amid the post-shogunate turmoil.

The Osafune school of Bizen maintained a relatively stable production system during this transition period. Since Bizen rarely became a direct battlefield of internal conflict, it could continue supplying swords to military commanders throughout the country. During the Kenmu period, the Osafune school expanded its workshop scale to meet surging demand and established mass-production systems.

Analysis of the Kenmu Restoration's Impact on Sword Forms

The Kenmu period was not an era that brought direct innovation in sword forms, but rather functioned as a "catalyst" for change. The turmoil of the Northern and Southern Courts that began after the collapse of Emperor Godaigo's government was the primary cause of major transformation in sword forms, though the starting point of that change can be traced to the Kenmu Restoration period.

What was significant in sword history regarding the Kenmu period was the simultaneous existence of three groups—samurai, aristocrats, and temples/shrines—as sword demanders. In the chaos following the shogunate's collapse, each faction attempted to monopolize swordsmiths, causing sword demand to disperse and diversify regionally. This led to the rise of regionally-based swordsmith groups during the Northern and Southern Courts period and the development of region-specific sword forms.

Kenmu Period Swords in Surviving Artifacts——Evaluation as Cultural Properties

Extant swords from around the Kenmu period are highly valued as National Treasures and Important Cultural Properties. Works attributed to Masamune of Sōshū are well-known as representative of this period, and pieces such as Honjō Masamune and Yoshimoto Samoji are believed to be transmissioned swords created around the period of Emperor Godaigo.

Though the Kenmu Restoration—a short-lived political experiment—ended in failure, in sword history its significance as an important nodal point in the transition from Kamakura order to Northern and Southern Courts diversity continues to be reevaluated.